Exercise in the Treatment of Repetitive, Self-Injurious, and Aggressive Behavior in Adults with Autism Spectrum Disorder: A Neurobiological Analysis

Abstract

Objective: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by markedly impaired social interaction and restricted/ repetitive patterns of behavior, interests, and activities. Maladaptive behaviors associated with ASD can include stereotyped, self-injurious, and aggressive behaviors. Current evidence-based interventions for ASD involve specialist availability, financial, time, and side effect constraints. Physical exercise has received increasing attention in the treatment of children with ASD, but research in adults is comparatively scarce. The purpose of this paper is to explore possible mechanisms by which exercise can reduce repetitive, self-injurious, and aggressive behaviors in adults with ASD. Methods: The literature on the neurobiology of exercise is reviewed and compared with the literature on the neurobiology of ASD. Information from this comparison is then used to formulate possible mechanisms by which exercise may reduce maladaptive behaviors in adults with ASD. Results: Plausible mechanisms for an exercise-induced beneficial effect on maladaptive behaviors in adults with ASD include modulation of neurotransmitter release and function, facilitation of endocannabinoid release, increased expression of neurotrophic factors, improved functional connectivity in higher-level cognitive networks, reduced oxidative stress, improved HPA axis function, treatment of comorbid depression, and reduction in amyloid beta deposition in cortical GABAergic neurons and subcortical structures. Conclusions: Future research should attempt to confirm the efficacy of exercise in reducing maladaptive behaviors in adults with ASD as well as the proposed mechanisms for such a relationship. Verification of these issues would have major implications in terms of supporting an evidence-based, inexpensive, widely available, and broadly beneficial treatment for adults with ASD.